http: always use regex for invalid path check

Using the "optimized" version was not significantly faster and even
slower for larger n.

lib/_http_client.js

@@ -41,33 +41,7 @@ const { outHeadersKey } = require('internal/http');
 const { nextTick } = require('internal/process/next_tick');
 const errors = require('internal/errors');
 
-// The actual list of disallowed characters in regexp form is more like:
-//    /[^A-Za-z0-9\-._~!$&'()*+,;=/:@]/
-// with an additional rule for ignoring percentage-escaped characters, but
-// that's a) hard to capture in a regular expression that performs well, and
-// b) possibly too restrictive for real-world usage. So instead we restrict the
-// filter to just control characters, spaces and two-byte characters.
-//
-// This function is used in the case of small paths, where manual character code
-// checks can greatly outperform the equivalent regexp (tested in V8 5.4).
-function isInvalidPath(s) {
-  var i = 0;
-  if (s.charCodeAt(0) <= 32 || s.charCodeAt(0) > 0xFF) return true;
-  if (++i >= s.length) return false;
-  if (s.charCodeAt(1) <= 32 || s.charCodeAt(1) > 0xFF) return true;
-  if (++i >= s.length) return false;
-  if (s.charCodeAt(2) <= 32 || s.charCodeAt(2) > 0xFF) return true;
-  if (++i >= s.length) return false;
-  if (s.charCodeAt(3) <= 32 || s.charCodeAt(3) > 0xFF) return true;
-  if (++i >= s.length) return false;
-  if (s.charCodeAt(4) <= 32 || s.charCodeAt(4) > 0xFF) return true;
-  if (++i >= s.length) return false;
-  if (s.charCodeAt(5) <= 32 || s.charCodeAt(5) > 0xFF) return true;
-  ++i;
-  for (; i < s.length; ++i)
-    if (s.charCodeAt(i) <= 32 || s.charCodeAt(i) > 0xFF) return true;
-  return false;
-}
+const INVALID_PATH_REGEX = /[\u0000-\u0020\u0100-\uffff]/;
 
 function validateHost(host, name) {
   if (host != null && typeof host !== 'string') {
@@ -117,13 +91,7 @@ function ClientRequest(options, cb) {
   var path;
   if (options.path) {
     path = String(options.path);
-    var invalidPath;
-    if (path.length <= 39) { // Determined experimentally in V8 5.4
-      invalidPath = isInvalidPath(path);
-    } else {
-      invalidPath = /[\u0000-\u0020\u0100-\uffff]/.test(path);
-    }
-    if (invalidPath)
+    if (INVALID_PATH_REGEX.test(path))
       throw new errors.TypeError('ERR_UNESCAPED_CHARACTERS', 'Request path');
   }